Existing telecommunications networks are hybrids of circuit and packet switched networks. They are also hybrids of wireless and wire line networks. Today there is a demand for converged networks that are multi-domain, multi-carrier and multi-technological. A connection may be established end-to-end from one network to another going through several other networks on its way. It will be appreciated that, as used herein, the term domain can refer to a network. Today there is an emerging need for inter-carrier technology and architecture which coordinates demand and supply between carriers, enables fast end-to-end provisioning based on control plane in-band signaling and inter-domain visibility, provides automatic unified authentication, authorization and security mechanisms for inter-carrier services, and enables an automatic unified billing mechanism for inter-carrier services. According to this architecture, such a network should be resilient, robust and scalable.
U.S. Pat. Nos. 6,516,195 and 5,875,238 deal with handover and billing in a cellular network. U.S. Pat. No. 6,516,195 describes a method and system for optimizing mobile telecommunications networks utilizing geographical positioning information. Initially, a particular telecommunications event, such as a handover event, call set-up event, a dropped call event, or a high bit error rate event, is designated, such that an occurrence of the particular telecommunications event automatically triggers geographical positioning of a mobile unit within a mobile telecommunications network. A geographical positioning request is then transmitted to a mobile location center within the telecommunications network, in response to an occurrence of the particular telecommunications event. Thereafter, geographical positioning information associated with the particular telecommunications event and the mobile unit is determined, in response to the transmission of the geographical positioning request to the mobile location center.
U.S. Pat. No. 5,875,238 describes a telecommunications switch serving a roaming mobile station, which transports the resulting billing records by setting up a communication link with an administrative billing center connected to a Signaling System No. 7 (SS7) telecommunications network by utilizing Transaction Capabilities Application Part (TCAP) signals.
U.S. Pat. No. 6,292,481 describes an inter-carrier signaling and usage accounting architecture for Internet telephony. A communication system providing telephony communication across combined circuit switched and packet switched networks, such as a telephone network and the Internet, provides an architecture and methodology for handling resource allocation, settlements, usage accounting, and usage allocation among carriers or service providers. This patent relates to establishing a phone call between domains of circuit and Internet Protocol (IP) data protocols.
U.S. Pat. No. 6,014,379 describes a telecommunications system wherein the dialing of a directory number, which has been forwarded, triggers an intelligent network signal which is directed to the Internet. The signal is transmitted through the Internet to a database in the Internet, where a forwarding number for the forwarded number is obtained. The database returns call set up directions which are used by the originating switching system to establish a voice link from the calling station to the station having the forwarded number. In another embodiment, where a number has been forwarded to a station that is connected only to the Internet, the Internet database may provide a domain name address. This address is then used to establish a link through the Internet between the calling and called station. In this instance, the Internet handles both the signaling and the voice connections.
However, all these patents deal with telephone call services in different technologies and multiple carriers. These services are point-to-point services, have a well-defined, unique Quality of Service (QoS) definition and a unique agreed upon addressing scheme (E.164, of the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T)). These patents do not provide a mechanism to assure QoS in each network, such that service end-to-end QoS requirements, as set forth in Service Level Agreements, are met. Conventional telephone addressing schemes cannot be used for general data services. Thus, these patents do not provide a global unique addressing scheme.
In addition to the patents described above, there is known a framework IPSphere that deals with inter-domain and inter-carrier services. The IPSphere is a framework for abstracting and composing multi-stakeholder telecommunications-based services both within and between service providers. However, IPSphere functions between Management Systems of owners of the network elements and Management Systems of the service providers. This framework is slow and not-automatic, since it operates on the management plane. The exchange of information among the management systems, and between management systems and network entities, is slow. In addition, this framework assumes a centralized management structure, where an administrative owner configures all the services through the management systems of the element owners. Implementation of this framework is not realistic in huge inter-carrier international networks, where services must be scalable and, hence, distributed service management is needed.
Another framework is known for providing inter-domain connectivity between Autonomous Systems (ASs), known as Border Gateway Protocol (BGP). Internal routing protocols are used inside each AS but cannot be used between ASs, because there is too much data to exchange. Also, some ASs do not trust each other and do not want to exchange their full routing information. BGP is an external routing protocol that works between ASs, while there is one central router per AS. The border gateways in different ASs exchange routing info via BGP, which is independent of the routing protocol beneath. The routing info contains network topology and metrics. The BGP communication is based on TCP (Transport Control Protocol). The BGP works in a huge network with many destination addresses, therefore it uses route aggregation based on IP prefixes. If a carrier does not want to publish its information to the other carriers, then sometimes BGP is unable to select the best route for a service due to lack of information, and only configures a “loose” route between gateways (namely, defines only the entry device and exit device of the network and does not describe the whole path inside the network). Since BGP is based on IP, the addressing is based on IP addresses inherent in the protocol and the protocol does not give a solution for general technology with different addressing schemes. Moreover, BGP handles routing and connectivity only, without authentication, authorization, billing and resource allocation and management.
Another existing framework is the Path Computation Element (PCE)-based model for path computation in large, multi-domain inter-layer networks. A PCE is an entity that is capable of computing a network path or route based on a network graph, and of applying computational constraints during the computation. The PCE is an application that can be located within a network node or component or on an out-of-network server. PCE can be implemented in many ways: a router, external server, etc.
PCE is able to compute a path while preserving confidentiality across multiple Service Providers' cores. The service provider is not required to divulge any information about its resources or topology in order to support inter-carrier path computation, but PCE may return partial paths by means of loose hops. PCE architecture provides path computation functionality only.
An existing network that has a single technology, but is multi-domain and multi-carrier is the Common Channel Signaling System #7 (SS7). SS7 separates the information required to set up and manage telephone calls in the Public Switched Telephone Network (PSTN) onto a separate packet switched network (the Signaling Network) rather than using the same circuit switched network that the telephone call, itself, is made on (the Voice Network). All nodes in the SS7 network are called Signaling Points (SPs). Each SP is identified by a unique address called a Point Code (PC). SPs have the ability to read a Point Code and determine if the message is for that node and the ability to route SS7 messages to another SP.
In SS7, only a guaranteed point to point 64 k timeslot is allocated per session on a pre-provisioned trunk. SS7 does not support protection, assuming protection exists on the physical layer. The routers and/or gateways, known as Signal Transfer Points (STPs) are arranged in a flat hierarchy relative to one another. In SS7, the STP has only static routing functionality, which relies on pre-computed routes by an external agent. In SS7, the signaling points trust each other and do not authorize or authenticate between themselves. Finally, the SS7 deals only with a single technology, namely TDM phone circuits.
There is also known in the art an E-NNI (external Network to Network Interface) as defined by MEF (the Metro Ethernet Forum) and OIF (Optical Internetworking Forum). This is a definition of a special interface that connects two networks while enabling separation between certain aspects of the network's data. The E-NNI is a reference point where two service providers meet in support of specified MEF services. The E-NNI definition enables a framework for inter carrier connection but it lacks definitions for global addressing, and it does not support automatic signaling and it does not support end to end provisioning, as its scope is only between two adjacent interfaces and not end to end.